This invention relates generally to dynamoelectric machines and more particularly to an electronically commutated electric motor having a printed circuit board assembly with position sensing devices and other components for controlling the motor and a method of manufacturing a printed circuit board assembly.
Dynamoelectric machines, in the form of electric motors, have numerous applications, such as for washing machines, compressors, and fans, to name only a few. An important part of the utility of the motor is that it can be manufactured inexpensively and yet provide a reliable, long lasting, quiet, low maintenance motor for an appliance or other machine. Thus, there is a need for a motor which can be easily and rapidly assembled without sacrificing quality and reliability. One source of delay and cost in the manufacturing process is the electrical connections that must be made in the motor. Electronically commutated motors have sensors, such as Hall devices, for detecting the position of the rotor. The sensors are electrically connected to one or more circuit boards which mount control and power components for energizing the windings. The components are mounted on the side of the circuit board facing away from the rotor. However, in some instances components may also be mounted on the side of the circuit board facing toward the rotor. The sensors must be positioned near the magnets of the rotor and thus cannot be mounted on the component side of the circuit boards. Typically, the control and power components are mounted on the circuit board, and then the components are soldered to the boards. In a second manufacturing step, the sensors are mechanically attached on the side opposite and then soldered to the circuit boards.